4种种植体系的水肥利用状况和经济效益比较

为了筛选适宜曲周县后老营村农业生产的较优种植体系并设计更好的种植体系,采用随机抽样调查的方法,对该村主要作物的种植体系及其水肥资源利用状况和经济效益进行了详细调查。结果表明:棉花-西瓜套作体系的水肥资源利用率最高,小麦-西瓜-玉米间套作体系的经济效益最好,棉花-西瓜套作体系次之,二者差异不显著。未来可以基于这2种种植体系重新设计新的种植体系,从而在生态、经济、环境等方面取得较好的综合效益。     

A review of soil NO transformation: Associated processes and possible physiological significance on organisms

NO emissions from soils and ecosystems are of outstanding importance for atmospheric chemistry. Here we review the current knowledge on processes involved in the formation and consumption of NO in soils, the importance of NO for the physiological functioning of different organisms, and for inter- and intra-species signaling and competition, e.g. in the rooting zone between microbes and plants. We also show that prokaryotes and eukaryotes are able to produce NO by multiple pathways and that unspecific enzymo-oxidative mechanisms of NO production are likely to occur in soils. Nitric oxide production in soils is not only linked to NO production by nitrifying and denitrifying microorganisms, but also linked to extracellular enzymes from a wide range of microorganisms.Further investigations are needed to clarify molecular mechanisms of NO production and consumption, its controlling factors, and the significance of NO as a regulator for microbial, animal and plant processes. Such process understanding is required to elucidate the importance of soils as sources (and sinks) for atmospheric NO.     

减少底肥施用量增加叶面施肥次数对玉米产量的影响

该试验目的是研究降低底肥施用量但是增加叶面肥施用次数方面对玉米产量的变化规律，旨在找出最经济的施肥方式以达到在保护环境的基础上提高经济效益的目的。试验表明，玉米产量随着底肥施用量的增加而提高，并且叶面肥喷施次数越多产量越高，每喷一次，可增加产量258~592.5 kg/hm2，增产幅度2.3%~5.6%。     

Utilization of Livestock''s Dejection as Biogas Origin in Building New Countryside in Heilongjiang Province--Developing Utilization of Biogas and Promoting Energy-saving and Emission Reduction

With the startup and execution of new socialistic countryside construction in Heilongjiang Province,the transition from castoff to resource is strengthened in the countryside,aiming at neat appearance of the countryside,clean production and saving energy.People produce biogas and provide the countryside with new energy by means of turning livestock's dejection into resources,composting of the plant and animal's leavings in the courtyard and even in the factory.It is helpful for the countryside to conserve t...     

广元市昭化区马尾松林下种植茯苓经济效益初探

本文主要介绍了广元市昭化区利用异常死亡的马尾松树林下种植茯苓的技术,对其种植成本和收益情况进行了初步分析。结果表明,利用死亡的马尾松林下种植茯苓,段木种植其平均产量可达48.82 kg,树蔸种植其平均产量可达10.02 kg,效益显著。同时可减少处置异常死亡树木的成本,值得大力推广。     

Effects of artificial light sources on accumulation of phytochemical contents in hydroponic lettuce

Lettuce is grown in different parts of the world and it is beneficial for health. Light condition is one of the most important environmental factor in regulating growth, development, and phytochemical accumulation in lettuce, particularly when lettuce is produced in a hydroponic system. Due to advances in technologies, artificial light sources have become increasingly capable of providing appropriate quality, intensity, and photoperiod of light in hydroponic lettuce production. This review highlights the progress of current research on the effects of artificial light regulation on growth and phytochemical accumulation in lettuce produced in hydroponic systems.     

水稻两段栽培技术在浉河区生产上的应用成效

介绍了水稻两段栽培技术的原理和方法,以及信阳市浉河区推广水稻两段栽培技术在减肥控氮、节本增效等方面取得的主要成效和主要做法。     

Does sand content in spawning substrate result in early larval emergence? Evidence from a lithophilic cyprinid fish

The spawning success of lithophilic salmonids is strongly influenced by the fine sediment content (“fines”) of spawning substrates, yet knowledge on the impacts of fines on the spawning of non‐salmonid lithophiles remains limited, despite their ecological and socio‐economic importance in European rivers. Consequently, the aim here was to use an ex‐situ experiment to investigate the impact of sand content on egg survival and timing of larval emergence of the surface‐spawning cyprinid European barbel Barbus barbus. Thirty incubator boxes within a recirculating system were filled with one of five experimental sediment mixtures (0%–40% sand by mass) that each contained 300 fertilised eggs at a depth of 50 mm. Emerged, free‐swimming larvae were captured and counted daily to assess grain‐size effects on larval survival and emergence. Specifically, total proportion of emerged larvae, cumulative daily proportion of emerged larvae and time required to reach 50% emergence were measured during the study. Whilst the proportion of sand in the sediments did not have a significant impact on egg‐to‐emergence survival (mean survival per treatment 75%–79%), it significantly affected the timing of larval emergence to the water column; early emergence was detected in treatments with elevated sand content (on average, 50% emergence after 12–13 days versus 19 days in the control). Similar to findings from salmonid studies, these results suggest high sand content in spawning gravels can influence timing of larval emergence and potentially cyprinid lithophilic fish survival.     

成龄油棕园林下间作生姜栽培技术与效益分析

介绍成龄油棕园林下间作生姜的栽培技术方法，并对间作效益进行分析，分析表明，间作效益的大小需考虑油棕园的荫蔽度。     

某8V150型柴油机平衡轴优化设计

文章以某8V150柴油机为例,对其平衡轴进行了优化设计,使得双轴平衡机构不但能够100％的平衡二级往复惯性力,而且所设计的平衡轴尺寸小,质量轻,能够有效地消减机体的倾覆力矩,改善了发动机的振动特性,满足了设计要求.